Contradiction with Proverbs 28:9
While Luke 18:6 demonstrates God's responsiveness to persistent prayer, Proverbs 28:9 suggests that God disregards the prayers of those who ignore His law, implying a conditional aspect to divine listening.
Proverbs 28:9: He that turneth away his ear from hearing the law, even his prayer [shall be] abomination.
Contradiction with Isaiah 59:2
Luke 18:6 portrays God as responsive, yet Isaiah 59:2 states that sins create a barrier between people and God, complicating the notion of assured divine response to all prayers.
Isaiah 59:2: But your iniquities have separated between you and your God, and your sins have hid [his] face from you, that he will not hear. [have hid: or, have made him hide]
Contradiction with Psalm 66:18
Luke 18:6 indicates God's responsiveness to prayer, but Psalm 66:18 notes that harboring iniquity in one's heart can lead to God not hearing prayer, which highlights a conditional element not seen in Luke 18:6.
Psalm 66:18: If I regard iniquity in my heart, the Lord will not hear [me]: